I want to make a couple of lanyards up for my sons and a couple of friends. I am trying to find a source for the foam tubing they use for padding in the neck area. I've done the Google Search and found some suppliers, but I don't have a need for the amount I would have to order from them. Any sources that sell small amounts of the stuff? All suggestions would be appreciated.

There's a cylindrical foam of about 3/8" dia. that's used on the outside edges of replacement windows as filler/weatherstripping. It even has a hole down the middle.
I couldn't find an example online, but I'm sure I'm not imagining it.
I've used the stuff for 'shrink tube slider' flies

Go to a Hardware store and look at weather stripping. Some of it is round and hollow.

Another way would be to wrap the lanyard with flat foam and cover it with heat shrink. You can shrink down the ends for a half inch or so and it will hold everything in place. You can buy some pretty big heat shrink and even get it in colors.

I made up a lanyard by braiding parachute cord, making a loop in the middle for a commonly used tool, and putting these on one strand of the cord for other doo-dads-

The braid both keeps it from digging into your neck and keeps the snaps from sliding around.

Almost forgot, at the ends of the braided section, tie all three strands in an overhand knot, leave one long for the loop, and cut and fuse the other two. (typing all this from memory, I'll try to go find the thing and take some pics)